1. Field of the Invention
The present invention relates to an improved pluggable electronic module configured to connect and/or convert data signals from a first serial transmission medium to a second serial transmission medium. A preferred embodiment of the invention is related to a GigaBit Interface Converter (GBIC) as defined by the GBIC specification (Small Form Factor document number: SFF-8053, revision 5.1a), the teaching of which is hereby incorporated herein by reference. Specifically, the preferred embodiment includes an interface converter module having four optical sub-assemblies, thus forming the multi-port pluggable transceiver. However, the improvements disclosed in this specification are applicable to high-speed data communication modules other than GBICs as well.
2. Discussion of the Background
The GBIC specification was developed by a group of electronics manufacturers in order to arrive at a standard small form factor transceiver module for use with a wide variety of serial transmission media and connectors. The specification defines the electronic, electrical, and physical interface of a removable serial transceiver module designed to operate at Gigabit speeds. A GBIC provides a small form factor pluggable module which may be inserted and removed from a host or switch chassis without powering off the receiving socket. The GBIC standard allows a single standard interface to be changed from a first serial medium to an alternate serial medium by simply removing a first GBIC module and plugging in a second GBIC having the desired alternate media interface.
The GBIC form factor defines a module housing which includes a first electrical connector for connecting the module to a host device or chassis. This first electrical connector mates with a standard socket which provides the interface between the host device printed circuit board and the module. Every GBIC has an identical first connector such that any GBIC will be accepted by any mating GBIC socket. The opposite end of the GBIC module includes a media connector, which can be configured to support any high performance serial technology. These high performance technologies include: 100 Mbyte multi-mode short wave laser without OFC; 100 Mbyte single-mode long-wave laser with 10 km range; Style 1 intracabinet differential ECL; and Style 2 intracabinet differential ECL.
The GBIC module itself is designed to slide into a mounting slot formed within the chassis of a host device. The mounting slot may include guide rails extending back from the opening in the chassis wall or faceplate. At the rear of the slot the first electrical connector of the module engages the mating socket which is mounted to a printed circuit board within the host device. The GBIC specification requires two guide tabs to be integrated with the electrical connector. As the connector is mated with the socket, the guide tabs of the connector engage similar structures integrally formed with the socket. The guide tabs are to be connected to circuit ground on both the host and the GBIC. The guide tabs engage before any of the contact pins within the connector and provide for static discharge prior to supplying voltage to the module. When the GBIC is fully inserted in this manner, and the connector fully mated with the socket, only the media connector extends beyond the host device chassis faceplate.
The GBIC specification document only provides for a single transmit function and a single receive function. For example, the optical GBIC at the media connector end accepts a duplex SC optical connector having one ferrule for transmitting data and one ferrule for receiving data. As the desire for increased bandwith continues, increasing density of media connectors is also desired. Therefore, it is an object of this invention to provide an interface converter module having multiple optical ports.